JP2019089471A - bicycle - Google Patents

Abstract

To provide a foldable bicycle in which a weight reduction of a vehicle body is achieved while mechanical strength of a two-foldable portion of a top tube is ensured.SOLUTION: A foldable bicycle whose hollow top tube 2 has a structure that can be folded into two, comprises: a first flange plate part 8 welded to one open end of a two-foldable portion; and a second flange plate part 9 welded to the other open end and butted against the first flange plate part 8. The first and second flange plate parts 8, 9 have holes 85, 95, respectively, penetrating a plate surface and thin-wall parts 84a, 84b, 94a, 94b which are thinner than a peripheral portion.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a folding bicycle, and in particular, the present invention relates to a folding bicycle in which a hollow top tube has a foldable structure.

  Folding bicycles are manufactured on the premise of carrying, and for that reason, weight reduction of the vehicle body is an important issue. As a material of a bicycle body frame, an alloy mainly composed of steel such as chromium molybdenum steel has been used conventionally. However, although steel is an ideal material as a frame material for bicycles such as mechanical strength and vibration absorption, it has the disadvantage that rust occurs and its weight is increased, and it is unsuitable as a frame material for folding bicycles .

  In order to reduce the weight of the vehicle body while securing mechanical strength, bicycles using an aluminum alloy as a material of the vehicle body frame are in widespread use. Aluminum alloys are currently used in all types of bicycles because they are lightweight, robust, resistant to rusting and inexpensive. In recent years, further weight reduction of a vehicle body is required, and a bicycle using a magnesium alloy as a material of a vehicle body frame has also been proposed (see, for example, Patent Document 1).

Patent No. 5881191

  There are various modes in the folding structure of the folding bicycle. In a folding bicycle having a structure that enables folding in the middle of the length of the top tube, in order to maintain the strength of the folding portion (joint portion) of the top tube, one of the open ends of the top tube is cut. The shield plate portion is welded, and the other open end is welded to the second shield plate portion to be abutted against the first shield plate portion, but the first and second shield plate portions are made of thick metal Since the plate material is used, the weight is increased, which hinders the weight reduction of the vehicle body.

  An object of the present invention is to provide a folding bicycle that achieves further weight reduction of a vehicle body while securing the mechanical strength of the half-folded portion of the top tube.

  A folding bicycle according to the present invention is a folding bicycle in which a hollow top tube has a structure that can be folded in half, and a first heel plate portion welded to one open end of the folded portion and the other open. And a second weir plate portion welded to the end and abutted against the first weir plate portion. At least one of a thin-walled portion having a small thickness with respect to the peripheral portion and a hole penetrating through the plate surface are formed in at least one of the first and second wedge plate portions.

  According to the present invention, it is possible to use thick metal plates as the first and second base plate portions. In addition, since at least one of the thin-walled portion and the hole portion is formed in at least one of the first weir plate portion and the second weir plate portion, each weir plate portion becomes lightweight, and the half-folded portion of the top tube Weight is reduced while mechanical strength is secured.

  In one embodiment of the present invention, one of the first and second sheathing plates is provided with a protruding edge which is circumferentially provided along the outer peripheral edge and into which the other sheathing plate is fitted. As a result, the first and second wedge plates do not shift relative to each other and are securely coupled, and rattle does not occur in the coupled portion.

Preferably, one side end of the first weir plate portion and the second weir plate portion is connected by a hinge mechanism, and the other side end can be opened and closed.
According to this embodiment, the top tube is folded in half and the folding bicycle is folded by opening the other end of each of the first and second tack plate portions with the hinge mechanism as the fulcrum. By closing the other end of each of the first and second wedge plates with the hinge mechanism as a fulcrum, the top tube is connected in a straight line, and the folding bicycle is assembled.

In one embodiment, the thin-walled portion and the hole portion have the hole at the central portion and the thin-walled portions at the upper and lower positions sandwiching the hole.
According to this embodiment, the first and second wedge plates become lightweight, and the mechanical strength of the half-folded portion of the top tube is secured while being lightened.

  In a preferred embodiment, since the thin-walled part has a hole penetrating the thin-walled part, the first and second wedge plate parts are further reduced in weight, and the two-folded part of the top tube is further reduced in weight Ru.

  According to this invention, weight reduction of the vehicle body can be realized while securing the mechanical strength of the half-folded portion of the top tube.

It is a front view showing the appearance of the folding bicycle of one embodiment. It is a front view which shows the half-folded part of top tube. It is a front view which shows the state which opened the 1st, 2nd each ratus board part. It is sectional drawing which follows the AA line of FIG. 3, (A) is a figure which shows the state which opened the 1st, 2nd roof plate part, (b) is each 1st, 2nd roof plate part It is a figure which shows the state which closed. FIG. 4 is a cross-sectional view of a first weir plate part taken along the line B-B in FIG. 3. FIG. 6 is a cross-sectional view of a second weir plate part taken along the line C-C of FIG. 3. It is a perspective view which shows the handle operation part of a lock mechanism.

  FIG. 1 shows an embodiment of a folding bicycle 1. The folding bicycle 1 is structured such that it can be folded in half at a substantially central length portion of a horizontal top tube 2 constituting a vehicle body frame 10. A joint portion 20 shown in FIG. 1.2 is formed in this double-folded portion, and a locking mechanism 100 for holding or releasing the joint state of the joint portion 20 is formed in the joint portion 20. It is assembled.

  At the rear end of the top tube 2, back forks 4 a and 4 b are provided in a left-right pair with the seat tube 3 facing in the vertical direction. The top tube 2 and the seat tube 3 and the seat tube 3 and the left and right back forks 4a and 4b are integrally connected by welding. At the front end of the top tube 2, front forks 6 a and 6 b are provided in a left-right pair with the head tube 5 facing in the vertical direction. The top tube 2 and the head tube 5 and the head tube 5 and the left and right front forks 6a and 6b are integrally connected by welding.

  A seat post 30 is supported by the seat tube 3 so as to be adjustable in height. A saddle 31 is attached to the upper end of the seat post 30. A stem 50 is supported by the head tube 5 so as to be adjustable in height. A handle 51 is provided at the upper end of the stem 50. The left and right back forks 4a and 4b extend obliquely downward, and the rear wheel 40 is rotatably supported between the rear end portions. The left and right front forks 6a and 6b extend almost directly downward, and the front wheel 60 is rotatably supported between the lower ends.

  The seat tube 3 is provided with a series of extensions 32 extending downward. A support pipe 22 is welded to the lower surface of the rear portion of the top tube 2, and a bushing 7 is attached by welding between the lower end of the extension 32 and the lower end of the support pipe 22. The bearing sleeve 7 rotatably supports the drive shaft 70. Crank arms 71 are attached to both ends of the drive shaft 70, respectively. A pedal 72 is attached to the tip of each crank arm 71. The rotation of the drive shaft 70 and the crank arm 71 is transmitted to the rear wheel 40 via the front gear 73 and the chain 74.

  The top tube 2, the seat tube 3, the back forks 4 a and 4 b, the head tube 5, and the front forks 6 a and 6 b constitute a vehicle body frame 10 forming a framework of the bicycle 1. Among the structural members of the vehicle body frame 10, at least the top tube 2 and the back forks 4a and 4b, preferably all the structural members of the vehicle body frame 10 are made of a wrought material of aluminum alloy or magnesium alloy. Alternatively, for example, the top tube 2 and the back forks 4a and 4b may be formed of a wrought material of magnesium alloy, and the other frame components may be formed of a wrought material of aluminum alloy.

  The back forks 4a and 4b are curved in a convex shape on the upper surface side, and extend obliquely downward while the distance between the two gradually increases from the front end to the rear end. The lower surface of each of the back forks 4a and 4b is supported by a support frame 41 connected to the extension portion 32 of the sheet tube 3 by welding. The central portions of the back forks 4a and 4b are connected by a connecting pipe (not shown).

  The inside of the top tube 2 is hollow, and the longitudinal cross-sectional shape in the direction perpendicular to the longitudinal direction is an elliptical shape that is vertically long. The reinforcing rib 21 may be integrally formed over the entire length at the lower position of the inner peripheral surface of the top tube 2 as indicated by a dashed dotted line in FIG.

  The top tube 2 has a central portion in the length direction divided into right and left portions, and a joint portion 20 which can be folded in two is formed between the divided open ends 23 and 24. The joint portion 20 is, as shown in FIGS. 3 to 6, a first weir plate portion 8 welded to one open end 23 of the top tube 2 which is a cut end face along the open end edge, The other open end 24 is provided with a second sheathing 9 that is welded along the open edge along the circumference and abutted against the first sheath 8. Each of the first and second wedge plates 8 and 9 has an area larger than the cross sectional area of the top tube 2 in the longitudinal direction, and the outer peripheral portion of each of the first and second wedge plates 8 and 9 protrudes outward from the outer peripheral surface of the top tube 2. In FIG. 5 and FIG. 6, 80 and 90 show welds that run around the open ends 23 and 24 of the top tube 2, respectively.

  Although each of the first and second base plate portions 8 and 9 is made of an aluminum alloy plate, other metal plate may be used as long as it is excellent in strength. The first weir plate portion 8 has a vertically elongated shape which is slightly larger than the second weir plate portion 9. As shown in FIG. 4A, a projecting edge portion 81 is provided along the outer peripheral edge of the first base plate portion 8 so as to surround the plate surface, as shown in FIG. 4B. The second weir plate 9 is fitted into the inside of the projecting edge 81 of the first weir plate 8.

  As shown in FIGS. 3 and 4 (A) and 4 (B), the first wedge plate portion 8 and the second wedge plate portion 9 are connected at one side end by the hinge mechanism 110, and the hinge mechanism 110 The other side end can be opened and closed with the pivot axis 111 of the frame of FIG. At the other ends of the first and second wedge plates 8 and 9, rectangular notches 82 and 92 for assembling the handle operating portion 101 of the lock mechanism 100 are formed.

  As shown in FIGS. 3 and 5, in the first sheathing plate portion 8, two thin portions 84a and 84b whose thickness is thinner than the thick portion 83a of the peripheral portion and the plate surface are pierced and penetrated. And a circular hole 85. The thin portions 84 a and 84 b are provided at upper and lower positions sandwiching the hole 85. Between the thin portions 84a and 84b and the holes 85, thick portions 83b and 83c continuous with the thick portion 83a of the periphery are interposed, and the thin portions 84a and 84b and the holes 85 are thick portions 83a. ~ 83 c. In each of the thin portions 84a and 84b, circular holes 86a and 86b are formed except for the peripheral portion. Each hole 86a, 86b penetrates each thin portion 84a, 84b.

  The second roof plate portion 9 has the same configuration as the first roof plate portion 8, and as shown in FIGS. 4 and 6, two thin wall portions 94a having a smaller thickness than the peripheral thick wall portion 93a. , 94b, and a circular hole 95 through which the plate surface penetrates. The thin portions 94 a and 94 b are provided at upper and lower positions sandwiching the hole 95. Between the thin portions 94a and 94b and the holes 95, thick portions 93b and 93c continuous with the thick portion 93a in the periphery are interposed, and the thin portions 94a and 94b and the holes 95 are thick portions 93a. ~ 93c. In each of the thin portions 94a and 94b, circular holes 96a and 96b are formed, leaving their peripheral portions. Each hole 96a, 96b penetrates each thin portion 94a, 94b.

  In this embodiment, in order to reduce the weight of the first and second sheathing plate parts 8 and 9, each of the sheathing plate parts 8 and 9 has thin portions 84a, 84b, 94a and 94b and holes 85, 86a and 86b. , 95, 96a, 96b, and on the other hand, the thin wall portion and the hole portion are arranged to be surrounded by the thick wall portions 83a to 83c, 93a to 93c in order to suppress the strength reduction. The area, shape, and number of pieces are appropriately set based on the strength test. The thin-walled portion and the hole may be provided only on one side of the weir plate portions 8 and 9, and at least one of the weir plate portions 8 and 9 may be provided with only one of the thin-walled portion and the hole.

  In addition, the first and second base plate portions 8 and 9 in this embodiment are formed by die casting of aluminum having thin portions 84a, 84b, 94a and 94b, and then holes 85, 95, 86a and 85b are formed. Although 86b, 96a, 96b are formed by cutting, it is not necessarily limited to such a manufacturing method.

  As shown in FIG. 2, the lock mechanism 100 includes a handle operating unit 101 and a handle holding unit 102. As shown in FIG. 7, the handle operation unit 101 is located at the handle 103 which is manually opened and closed, and at the notch 82 of the first cover plate 8, and the upper and lower ends are pivoted to the first cover plate 8. A first support shaft 104 which is supported freely movably, and a second support shaft 105 which is located at the notch 92 of the second anchor plate 9 and whose upper and lower ends are supported by the second anchor plate 9; It contains. The handle 103 is supported at its base end by the second support shaft 105 of the second anchor plate portion 9, and when the first and second anchor plate portions 8 and 9 are butted, the second The up and down movement is possible with respect to the outer peripheral surface of the top tube 2 by using the support shaft 105 as a fulcrum.

  A rod 107 is bridged between the first support shaft 104 of the first anchor plate portion 8 and the third support shaft 106 rotatably supported at the middle portion of the handle 103. When the handle 103 is pulled to close the opened first and second wedge plate portions 8 and 9, the second wedge plate portion 9 is pulled to the first wedge plate portion 8 by the rod 107, and the first , The second plate parts 8 and 9 are closely butted against each other.

  The handle holding portion 102 includes a pick-up 108 pivotally supported rotatably on the outer peripheral surface of the top tube 2 and a protruding shaft 109 protruding upward at a position of the third support shaft 106 of the handle 103. It is. When the handle 108 is turned over the top tube 2 and the image pickup 108 is turned to the side of the handle 103, the projecting shaft 109 engages with a recess (not shown) inside the image pickup 109, and the handle 103 is erected. Operation is regulated. When the photographing 109 is turned in the opposite direction, the protruding shaft 109 and the photographing 108 are disengaged, and the handle 103 is released from the restraint state.

  In addition, if the lock mechanism 100 can hold the coupled state of the joint portion 20, that is, the state in which the first and second wedge plate portions 8 and 9 abut each other, the above-described embodiment is implemented. It is not limited to the embodiment.

In the folding bicycle 1 described above, the first heel plate portion 8 is welded to one open end 23 of the half-folded portion of the top tube 2, and the second heel plate portion 9 is welded to the other open end 24 to form a joint. Since the portion 20 is configured, the bonding strength of the joint portion 20 is enhanced, and the mechanical strength of the folded portion of the top tube 2 is enhanced.
On the other hand, the thin wall portions 84a and 84b and the hole 85 are formed in the first base plate portion 8, and the thin wall portions 94a and 94b and the hole 95 are formed in the second base plate portion 9, respectively. The second base plate portions 8 and 9 become lightweight, and the weight reduction of the joint portion 20 can be achieved. Further, since the holes 86a and 86b are formed in the thin portions 84a and 84b of the first sheathing plate 8 and the holes 96a and 96b are formed in the thin portions 94a and 94b of the second sheathing plate 9, respectively. The respective weight plate portions 8 and 9 are further reduced in weight, and the weight reduction of the joint portion 20 is further enhanced.

  In the first weir plate 8, the hole 85 is at the central portion, the thin portions 84 a and 84 b are at the upper and lower positions sandwiching the hole 85, and in the second weir plate 9, the hole 95 is at the central portion Thin portions 94a and 94b are respectively provided at upper and lower positions sandwiching the hole 95, and the periphery is surrounded by the thick portions 83a and 83b, and between the hole 85 and the thin portions 84a and 84b, and the hole 95 Since the thick parts 83b, 83c, 93b, 93c exist between the thin part 94a and the thin part 94b, the mechanical strength of the joint part 20 is not lost, and the weight of the vehicle body is reduced.

  In order to fold the folding bicycle 1, the handle operating portion 101 and the handle holding portion 102 of the lock mechanism 110 are operated to release the lock, and then the hinge mechanism 110 is used as a fulcrum of the first and second heel plate portions 8 and 9. By opening the other end, the top tube 2 is folded in half and can be folded.

  Next, in order to assemble the folded bicycle 1, the other side ends of the first and second wedge plate portions 8 and 9 are closed with the hinge mechanism 110 as a fulcrum, and the second wedge plate portion 9 is The top tube 2 is connected in a straight line by being fitted into the projecting edge 81 of the heel plate 8, and further, the handle operating portion 101 and the handle holding portion 102 of the lock mechanism 110 are operated and locked. The assembly of the bicycle is complete.

DESCRIPTION OF SYMBOLS 1 Folding bicycle 2 top tube 8 1st board | plate part 9 2nd board | plate board part 23, 34 open end 80, 90 welding part 83a, 83b, 83c, 93a, 93b, 93c thick-walled part 84a, 84b, 94a, 94b Thin portion 85, 86a, 86b, 95, 96a, 96b Hole 110 Hinge mechanism

Claims (5)

  A folding bicycle having a hollow top tube in a foldable structure, wherein a first weir plate portion welded to one open end of the folded portion and a first open plate welded to the other open end. And at least one of the first and second sheathing plate portions has a thin-walled portion having a thickness smaller than that of the peripheral portion. The folding bicycle in which at least one of the hole parts which penetrate a plate surface is formed.   The folding bicycle according to claim 1, wherein one of the first heel plate portion and the second heel plate portion is provided with a projecting edge portion which is provided along the outer peripheral edge and into which the other heel plate portion is fitted.   The folding bicycle according to claim 1 or 2, wherein one side end of the first weir plate portion and the second weir plate portion is connected by a hinge mechanism, and the other side end can be opened and closed.   The folding bicycle according to claim 1, wherein the thin wall portion and the hole portion have a hole portion at a central portion and a thin wall portion at upper and lower positions sandwiching the hole portion.   The folding bicycle according to claim 1 or 4, wherein the thin-walled portion has a hole penetrating the thin-walled portion.